Closure Having a Segmented Locking Ring

ABSTRACT

A pressure closure having a round door with an arcuate locking ring having a plurality of arcuate locking ring segments connected by at least one connecting ring movably retained therewith proximate an outer circumference of an outer surface of the door. The locking ring segments may have at least one cavity extending through the arcuate length thereof. An arcuate connecting ring extends through each cavity in the locking ring segments retaining them together to form the locking ring. Alternatively, the connecting ring connects the locking ring segments together with connecting ring retaining links cooperating with the connecting ring and locking ring segments. Optionally, the cross-sectional configuration of the connecting ring is rounded. Advantageously, the optional at least one cavity extending through the locking ring segments has an axial opening extending the arcuate length of each locking ring segment. The axial opening may have a width less than or greater than the diameter of the locking ring extending therethrough. Optionally, the locking ring segments may have protuberances and fitting recesses on adjacent circumferential ends. Furthermore, connecting ring retaining links may be placed between a plurality of adjacent locking ring segments securing the connecting ring into cavities in the locking ring segments or securing the connecting ring proximate solid locking ring segments.

CROSS-REFERENCE TO RELATED APPLICATION

This application under 35 USC § 119(e), claims priority to, and benefit from, U.S. Provisional Application Ser. No. 60/976,997, filed on Oct. 2, 2007, entitled “Closure Having a Segmented Locking Ring,” which is currently pending, naming the above-listed individual as the sole inventor.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to closures for pressure vessels or pipes and more specifically to locking members for pressure closures.

2. Description of the Related Art

Closures for pressure vessels and pipes typically comprise a round door adapted to fit an aperture in the body of the vessel, pipe, or hub extending therefrom. The aperture has an inner circumferential groove for supporting a portion of a locking member. The doors have locking member(s), or portions thereof, proximate a circumferential portion of an outer surface of the door wherein the locking member is engaged to cooperate with the groove about the aperture after the door is closed and seated in the aperture. The locking members of the prior art are typically comprised of a plurality of arms or blocks slidably mounted adjacent the outer periphery of the door and movable from an unlocked position to a locked position. In an unlocked position, the locking member(s) is within the periphery of the outer surface of the door. In a locked position, a part of the locking member(s) protrudes beyond the periphery for engagement with the circumferential groove in the aperture.

Known configurations of locking members include arms or blocks that rotate or extend outwardly, arcuate or “C” shaped rings, slotted as well as segmented, that expand to a locking configuration and contract to an unlocking configuration. Locking member(s) of the prior art have load bearing surfaces that engage an external surface of the annular groove in the hub or vessel and a load bearing surface that engages a portion of the external surface of the door. When the internal surface of the door is subjected to pressure, the resultant force is transferred from the external surface of the door to the external surface of the annular groove about the aperture through the locking member(s) wherein an internal load bearing surface cooperates with the external surface of the door and an external load bearing surface cooperates with the external load bearing surface of the annular groove of the hub.

SUMMARY OF THE INVENTION

A pressure or vacuum closure having a round door with an arcuate locking ring having a plurality of arcuate locking ring segments is provided. The plurality of locking ring segments are connected, end to end, by at least one connecting ring forming the locking ring having an arcuate “C” shaped configuration. The locking ring is movably retained proximate an outer circumference of an external surface of the door with retaining clips. The locking ring is suitable to expand and contract wherein an outer circumferential portion of the locking ring is suitable to engage a groove within an inner circumferential surface of an opening when the locking ring is in an expanded orientation and is suitable to contract to a circumference less than the inner circumference of the opening. When the locking ring is in an expanded locked position, an outer circumferential portion of the locking ring extends beyond the circumference of the door and is received into the groove within the inner annular surface of the pipe, container, vessel, or hub extending therefrom.

The locking ring segments may have at least one cavity extending through the arcuate length thereof with a portion of the connecting ring extending therethrough, retaining the locking ring segments together to form the locking ring. Each cavity has a greater cross-sectional area than the cross-sectional area of the connecting ring extending therethrough. Optionally, the cross-sectional configuration of the connecting ring and cavities through which it extends is rounded. At least one cavity(s) extending through the locking ring segments may have an axial opening extending the arcuate length of each locking ring segment. Axial, as used herein, refers to an orientation with respect to the longitudinal axis of the hub when the door is in a closed position within the hub. The axial opening may have a width less than or greater than the diameter of the locking ring extending therethrough. Optionally, the locking ring segments have protuberances and fitting recesses on adjacent circumferential ends. Furthermore, connecting ring retaining links may be placed between a plurality of adjacent locking ring segments securing the connecting ring(s) into the cavities.

Alternatively, the arcuate locking ring has a plurality of arcuate locking ring segments with a connecting ring retaining link fastened between each arcuate segment and each end face of the arcuate locking ring. In this embodiment, each connecting ring retaining link has a portion extending radially inward from an inner radial surface of the arcuate locking ring. Radial, as used herein, refers to an orientation with respect to the radius of the hub when the door is in a closed position within the hub. The inward extending portion has an aperture therein for receiving the connecting ring. The connecting ring arcuately extends through each aperture in the connecting ring retaining links, thus retaining each locking ring segment together to form the arcuate locking ring.

BRIEF DESCRIPTION OF THE FIGURES

In order that the invention may be better understood, embodiments of the closure in accordance with the present invention will now be described by way of examples. These embodiments are not to limit the scope of the present invention as other embodiments of the closure of the present invention will become apparent to one having ordinary skill in the art upon reading the instant description. Examples of the present invention are shown in figures wherein:

FIG. 1 is a perspective view of an embodiment of a closure in a closed representation showing a door within a hub and components thereof on an outer surface of the door.

FIG. 2A is a frontal view of the closure of FIG. 1 in a closed representation showing the orientation of a locking ring and actuator assembly with respect to a door in a closed position within a hub.

FIG. 2B is a cross-sectional view of the closure of FIG. 2A showing the orientation of the locking ring segment, connecting ring, hinge assembly, safety system assembly, and sealing gasket with respect to a door and a hub.

FIG. 3A is a side view of the closure of FIG. 1 in an open representation showing the orientation of a locking ring and actuator assembly with respect to a door and a hub.

FIG. 3B is a cross-sectional view of the closure of FIG. 3A showing the orientation of the locking ring in a retracted, open orientation about a door.

FIG. 4 is a cross-sectional cut-away view of the closure of FIG. 2B showing the cooperation of the locking ring segment and a sealing gasket with the hub.

FIG. 5 is a frontal view of the locking ring of FIG. 1 showing locking ring segments of an expanded locking ring and an expansion gap between end faces of the locking ring.

FIGS. 6A-6L are cross-sectional views of several embodiments of a locking ring showing configurations of locking ring segments of the locking ring having cavities cooperating with at least one connecting ring and the cooperation therebetween.

FIGS. 6N and 6M are cut-away views of several embodiments of a locking ring showing configurations of locking ring segments of the locking ring, connecting rings, connecting ring retaining links, and cooperation therebetween.

FIG. 7 is a perspective view of a locking ring showing locking ring segments cooperating with a connecting ring about an inner radial surface thereof with a plurality of connecting ring retaining links.

FIGS. 7A and 7B are top and side views, respectively, of the locking ring of FIG. 7 showing the engagement and cooperation of the connecting ring retaining links and fasteners with the locking ring segments.

FIG. 7C is a cross-sectional view of a locking ring segment and connecting ring of the locking ring of FIG. 7 showing the orientation between the connecting ring and locking ring.

FIG. 7D is a front view of a connecting ring retaining link of FIG. 7.

FIGS. 8A through 8F show embodiments of sealing gaskets that may be seated within a circumferential groove about an inner surface of a door.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

FIG. 1 is a perspective view of closure 100 in a closed representation. Closure 100 comprises door 104 hingedly attached to the outermost annular surface of hub 102 with hinge assembly 108 and seated within an inner annular surface of hub 102. In this closed orientation, segmented locking ring 106 is expanded having a portion visible about an external surface of door 104 and a portion within groove 116 (shown in FIG. 2 b) in an inner annular surface of hub 102. Also shown here is locking ring actuator assembly 110 comprising crank lever 112 rotatingly engaging crank spring 114 and locking ring 106 via weldment. In this locked position, crank lever 112 has been rotated clockwise from an unlocked position wherein crank spring 114 applies a separating force proximate one end of locking ring 106 and crank lever 112 applies a separating force proximate the other end of locking ring 106 expanding locking ring 106. Between the end faces 134 and 136 of locking ring 106 is locking segment 115 supported therein with locking segment assembly 113. Locking segment 115 has a portion in the inner annular groove 116 in hub 102 between the end faces 134 and 136 of locking ring 106 which prevents the contraction of locking ring 106 when in an expanded locked position. Clips 111 moveably hold locking ring 106 proximate the outer circumferential edge of the outer surface of door 104 allowing locking ring 106 to expand into and contract out of groove 116 in hub 102.

FIGS. 2 a and 2 b show door 104 in a closed orientation within hub 102. Door 104 has outwardly tapered outer load bearing surface 140 proximate the inner annular surface of hub 102 which cooperates with axially inward facing load bearing surface 122 (shown in FIG. 4) of locking ring 106. Hub 102 has inner annular groove 116 proximate the outer circumferential surface of door 104. The axially inward facing load bearing surface of inner annular groove 116 cooperates with axially outward facing load bearing surface 123 (shown in FIG. 4) of locking ring 106. Locking ring 106 is shown as a plurality of locking ring segments 118 retained together with connecting ring 120. Locking ring 106 comprising a plurality of locking ring segments 118 and connecting ring 120 may have a plurality of configurations forming an expandable locking ring 106 with axially inward and outward facing load bearing surfaces 122 and 123 (shown in FIG. 4).

Also shown in FIGS. 2 a and 2 b is safety locking segment assembly 113 having locking segment 115. Locking segment assembly 113 comprises pressure warning screw 126 having threaded end 130 that cooperates with threaded aperture 132 in door 104. Aperture 132 is in flow communication with the wetted internal portion of hub 102 and ambient air when pressure warning screw 126 is removed. About an outer annular surface of pressure warning screw 126 is “L” shaped locking segment connecting bracket 124 which has an aperture in one leg about an outer portion of pressure warning screw 126. Pins 128 extend through apertures in pressure warning screw 126 and cooperate within each side of bracket 124 so that when pressure warning screw 126 is removed, the assembly remains inseparable. When pressure warning screw 126 is threaded into aperture 132, as shown, locking segment connecting bracket 124 which is adjacent or connected to an inner radial surface of locking segment 115 constrains locking segment 115 between end faces 134 and 136 of locking ring 106. In this locked position, locking ring 106 is prohibited from contracting and keeping a portion of locking ring 106 within groove 116. Loosening pressure warning screw 126 releases locking segment 115 so that it may be removed from hub 102. When in the locked position, as shown here, locking segment 115 cooperates with each end, 134 and 136, of locking ring 106 retaining it in an expanded locked orientation within inner annular groove 116. Advantageously, at least one of the threads within the inner annular surface of aperture 132 or on the outer annular surface of threaded end 130 of pressure warning screw 126 has a groove therein or other configuration allowing an amount of pressurized gasses within hub 102 to escape making a whistling sound or other warning sound about gasket 139 when pressure warning screw 126 is loosened.

Sealing gasket 138 is shown within a circumferential groove about an inner surface of door 104 proximate an outer circumference. Sealing gasket 138 may be of any configuration as is known in the art which imparts a seal between an inner surface of door 104 and hub 102. For example, seal 138 may be an o-ring seal, an energized seal comprised of a single piece or a plurality of pieces including an anti-extrusion ring thereabout, or have other configurations as is known in the art. For example, seal 138 may be fluid or spring energized. Seal 138 may be extruded or molded and may have an anti-extrusion ring about an outer circumferential surface.

FIGS. 3 a and 3 b show door 104 in an open orientation hingedly attached to hub 102 with hinge assembly 108. Closure 100 has locking segment assembly 113 removed therefrom wherein a gap is formed between each end face 134 and 136 of locking ring 106. End faces 134 and 136 are then drawn together in the gap created with the removal of locking segment 115 (shown in FIG. 2A). Door 104 has locking ring 106 contracted to an inner portion of outwardly tapered outer load bearing surface 140 and removed from groove 116.

FIG. 4 shows the cooperation between segmented locking ring 106 with a load bearing portion in annular groove 116 in the inner annular surface of hub 102. Locking ring segment 118 has axially inward and outward facing load bearing surfaces 122 and 123. Inward facing load bearing surface 122 cooperates with outwardly tapered outer load bearing surface 140 of door 104. Outward facing load bearing surface 123 cooperates with an axially inward facing load bearing surface of inner annular groove 116. This configuration transfers the pressure applied to the inner surface of door 104 to locking ring 106 and inner annular groove 116.

FIG. 5 shows a front view of segmented locking ring 106 having connecting ring 120. Locking ring 106 has a plurality of locking ring segments 118 retained together with connecting ring 120 forming arcuate or “C” shaped segmented locking ring 106. Locking ring 106 has end faces 134 and 136 movable towards and away from each other allowing radial expansion and contraction of the locking ring 106. Connecting ring 120 resides within an arcuate cavity within each locking ring segment 118 and is comprised of a flexible material, such as spring steel, suitable for expanding and contracting locking ring 106.

FIGS. 6A-6L show several embodiments of a locking ring and associated connecting ring(s). FIG. 6A shows locking ring 106 having connecting ring 120 within arcuate cavity 109. Connecting ring 120 is comprised of a flexible material having a round cross-section suitable for retaining locking ring segments 118 together and suitable for enabling locking ring 106 to radially expand and contract into an open and closed orientation. In a closed orientation, locking ring 106 is expanded wherein an outer circumferential portion is suitable to engage a groove within an inner circumferential surface of an opening. In an open orientation, locking ring 106 is contracted to a circumference less than the inner circumference of the outer portion of the opening. Arcuate cavity 109 has an axially outward opening in locking ring 106 and a larger diameter than that of connecting ring 120 forming a space between an inner surface of locking ring segment 118 and connecting ring 120 providing room for connecting ring 120 to radially expand and contract without placing excessive force on an internal surface of locking ring segment 118. Arcuate cavity 109 shows an axially outward opening in locking ring 106. This axial opening is optional as it is formed during an advantageous method of removing material from an internal portion of locking ring segment 118 forming arcuate cavity 109 and is not critical to the present invention as other methods of manufacture known in the art may produce arcuate cavity 109 within ring segment 118 without an opening in an outer surface of ring segment 118.

Locking ring 106 has axially inward and outward facing load bearing surfaces 122 and 123 being frustoconical surfaces to slidingly engage load bearing surface 140 of hub 102 and a load bearing surface within groove 116 in hub 102. Load bearing surfaces 122 and 123 are shown as being substantially parallel and form an angle α with respect to the central axis of locking ring 106. Advantageously, angle α is between about 85° and 0° and more advantageously at least 30°. Even though in the embodiments shown, load bearing surfaces 122 and 123 are shown as being substantially parallel, it is to be understood that load bearing surfaces 122 and 123 may be divergent. Having divergent load bearing surfaces 122 and 123 forms a wedge shaped cross-section within locking ring 106. This wedge configuration causes an expanding force to be placed on locking ring 106 when an outward force is exerted by load bearing surface 140 of door 104 forcing load bearing surface 123 against the load bearing surface within groove 116 in hub 102.

FIG. 6B shows locking ring 206 having connecting ring 220 within arcuate cavity 209 in locking ring segment 218. Connecting ring 220 has a horizontal oval shaped cross-section suitable for retaining locking ring segments 218 together and suitable for enabling locking ring 206 to radially expand and contract into an open and closed orientation. Arcuate cavity 209 also has a horizontal oval configuration and has an axially outward opening in locking ring 206. Arcuate cavity 209 has a larger diameter than that of connecting ring 220 forming a space between an inner surface of locking ring segment 218 and connecting ring 220 providing room for connecting ring 220 to radially expand and contract without placing excessive force on an internal surface of locking ring segment 218. Locking ring 206 has axially inward and outward facing load bearing surfaces 122 and 123.

FIG. 6C shows locking ring 306 having connecting ring 120 within arcuate cavity 309 in locking ring segment 318. Connecting ring 120 has a round cross-section suitable for retaining locking ring segments 318 together and suitable for enabling locking ring 306 to radially expand and contract into an open and closed orientation. Arcuate cavity 309 also has a round configuration and has an axially inward opening in locking ring 306. Arcuate cavity 309 has a larger diameter than that of connecting ring 120 forming a space between an inner surface of locking ring segment 318 and connecting ring 120 providing room for connecting ring 120 to radially expand and contract without placing excessive force on an internal surface of locking ring segment 318. Locking ring 306 has axially inward and outward facing load bearing surfaces 122 and 123.

FIG. 6D shows locking ring 406 having connecting ring 420 within arcuate cavity 409 in locking ring segment 418. Connecting ring 420 has a vertical oval shape cross-section suitable for retaining locking ring segments 418 together and suitable for enabling locking ring 406 to radially expand and contract into an open and closed orientation. Arcuate cavity 409 also has a vertical oval configuration and has an axially outward opening in locking ring 406. Arcuate cavity 409 has a larger diameter than that of connecting ring 420 forming a space between an inner surface of locking ring segment 418 and connecting ring 420.

FIG. 6E shows locking ring 506 having connecting rings 120 within arcuate cavities 109 and 509 in locking ring segment 518. Connecting rings 120 have a round cross-section for retaining locking ring segments 518 together and are suitable for enabling locking ring 506 to radially expand and contract into an open and closed orientation. Arcuate cavity 109 has a round configuration and has an axially outward opening in locking ring 506. Arcuate cavity 509 has a round configuration and has an axially inward opening in locking ring 506. Arcuate cavities 109 and 509 have larger diameters than that of connecting rings 120 forming a space between an inner surface of locking ring segment 518 and connecting rings 120.

FIG. 6F shows locking ring 606 having connecting ring 620 within arcuate cavity 609 in locking ring segment 618. Connecting ring 620 has a round cross-section suitable for retaining locking ring segments 618 together and suitable for enabling locking ring 606 to radially expand and contract into an open and closed orientation. Arcuate cavity 609 also has a round configuration and has a radially inward opening in locking ring 606. Arcuate cavity 609 has a larger diameter than that of connecting ring 620 forming a space between an inner surface of locking ring segment 618 and connecting ring 620.

FIG. 6G shows locking ring 706 having connecting ring 720 within arcuate cavity 709 in locking ring segment 718. Connecting ring 720 has a round cross-section suitable for retaining locking ring segments 718 together and suitable for enabling locking ring 706 to radially expand and contract into an open and closed orientation. Arcuate cavity 709 also has a round configuration and has a radially outward opening in locking ring 706. Arcuate cavity 709 has a larger diameter than that of connecting ring 720 forming a space between an inner surface of locking ring segment 718 and connecting ring 720.

FIG. 6H shows locking ring 806 having connecting rings 820 and 822 within arcuate cavities 809 and 811 in locking ring segment 818. Connecting rings 820 and 822 have a round cross-section for retaining locking ring segments 818 together and are suitable for enabling locking ring 806 to radially expand and contract into an open and closed orientation. Arcuate cavity 809 has a round configuration and has a radially outward opening in locking ring 806. Arcuate cavity 811 has a round configuration and has a radially inward opening in locking ring 806. Arcuate cavities 809 and 811 have larger diameters than that of connecting rings 820 and 822 forming a space between an inner surface of locking ring segment 518 and connecting rings 820 and 822.

FIG. 6I shows locking ring 906 having connecting ring 920 within arcuate cavity 909 in locking ring segment 918. Connecting ring 920 has a rectangular cross-section suitable for retaining locking ring segments 918 together and suitable for enabling locking ring 906 to radially expand and contract into an open and closed orientation. Arcuate cavity 909 also has a rectangular configuration and has a radially outward opening in locking ring 906. Arcuate cavity 909 has a larger cross-sectional area than that of connecting ring 920 forming a space between an inner surface of locking ring segment 918 and connecting ring 920.

FIG. 6J shows locking ring 1006 having connecting ring 1020 within arcuate cavity 1009 in locking ring segment 1018. Connecting ring 1020 has a rectangular cross-section suitable for retaining locking ring segments 1018 together and suitable for enabling locking ring 1006 to radially expand and contract into an open and closed orientation. Arcuate cavity 1009 also has a rectangular configuration and has an axially inward opening in locking ring 1006. Arcuate cavity 1009 has a larger cross-sectional area than that of connecting ring 1020 forming a space between an inner surface of locking ring segment 1018 and connecting ring 1020.

FIG. 6K shows locking ring 1106 having connecting ring 1120 within arcuate cavity 1109 in locking ring segment 1118. Connecting ring 1120 has a rounded cross-section with a hollow center suitable for retaining locking ring segments 1118 together and suitable for enabling locking ring 1106 to radially expand and contract into an open and closed orientation. Arcuate cavity 1109 also has a round configuration and has an axially outward opening in locking ring 1106. Arcuate cavity 1109 has a larger diameter than that of connecting ring 1120 forming a space between an inner surface of locking ring segment 1118 and connecting ring 1120. Locking ring segment 1118 has a substantially rectangular configuration with load bearing surfaces 122 and 123 and shows that the cross-sectional configuration of the locking ring of the present invention may have most any cross-sectional configuration.

FIG. 6L shows locking ring 1206 having connecting rings 1220 and 1222 within arcuate cavities 1209 and 1211 in locking ring segment 1218. Connecting rings 1220 and 1222 have a round cross-section for retaining locking ring segments 1218 together and are suitable for enabling locking ring 1206 to radially expand and contract into an open and closed orientation. Arcuate cavity 1209 has a round configuration and has an axially outward opening in locking ring 1206. Arcuate cavity 1211 has a round configuration and has an axially inward opening in locking ring 1206. Arcuate cavities 1209 and 1211 have larger diameters than that of connecting rings 1220 and 1222 forming a space between an inner surface of locking ring segment 1218 and connecting rings 1220 and 1222.

FIG. 6M shows locking ring 1306 having connecting ring 120 within arcuate cavity 1309. Connecting ring 120 is comprised of a flexible material having a round cross-section suitable for retaining locking ring segments 1318 together and suitable for enabling locking ring 1306 to radially expand and contract into an open and closed orientation. It is to be understood that connecting ring 120 may have any cross-sectional configuration such as oval, rectangular, or even triangular. In a closed orientation, locking ring 1306 is expanded wherein an outer circumferential portion is suitable to engage a groove within an inner circumferential surface of an opening. In an open orientation, locking ring 1306 is contracted to a circumference less than the inner circumference of the outer portion of the opening exterior of the groove. Arcuate cavity 1309 has an axially outward opening in locking ring 1306 and a larger diameter than that of connecting ring 120 forming a space between an inner surface of locking ring segment 1318 and connecting ring 120 providing room for connecting ring 120 to radially expand and contract without placing excessive force on an internal surface of locking ring segment 1318. Arcuate cavity 1309 has an axially outward opening in locking ring 1306 with a width proximate the diameter of cavity 1309. This axial opening configuration permits more cost effective tooling of locking ring segment 1318 in making cavity 1309 at specified tolerances. Protuberance 1321 extends from one circumferential end of locking ring segment 1318 and engages a like shaped recess on the other circumferential end of an adjacent locking ring segment 1318 (not shown). Connecting ring retaining link 126 has aperture 128 b suitable to receive protuberance 1321 and aperture 128 a suitable to receive connecting ring 120. A connecting ring retaining link 126 is placed between a plurality of locking ring segments 1318 in locking ring 1306 about locking ring 120 and protuberances 1321 retaining connecting ring 120 within cavity 1309.

FIG. 6N shows locking ring 1406 having connecting rings 1220 and 1222 within arcuate cavities 1409 and 1411 in locking ring segment 1418. Connecting rings 1220 and 1222 have round cross-sections for retaining locking ring segments 1418 together and are suitable for enabling locking ring 1406 to radially expand and contract into an open and closed orientation. Arcuate cavities 1409 and 1411 have round configurations and have axially outward and inward openings, respectively, in locking ring 1406. Arcuate cavities 1409 and 1411 have diameters greater than that of connecting rings 1220 and 1222 forming a space between an inner surface of locking ring segment 1418 and connecting rings 1220 and 1222. Arcuate cavities 1409 and 1411 have axially outward and inward openings, respectively, in locking ring 1406 with a width proximate the diameter of cavities 1409 and 1411 respectively. These axial openings permit more cost effective tooling of locking ring segment 1418 in making cavities 1409 and 1411 at specified tolerances. Connecting ring retaining link 126 has aperture 128 b suitable to receive connecting ring 1222 and aperture 128 a suitable to receive connecting ring 1220. A connecting ring retaining link 126 is placed between a plurality of adjacent locking ring segment 1418 in locking ring 1406 about locking rings 1220 and 1222 retaining connecting rings 1220 and 1222 within cavities 1409 and 1411 respectively. Advantageously, a connecting ring retaining link 126 is placed between each adjacent locking ring segment 1418. It is to be understood that apertures 128 a and 128 b may be joined to form a single aperture wherein connecting ring retaining link 126 and still be within the scope of the present invention.

FIG. 7 shows a perspective view of segmented locking ring 1506 having connecting ring 1520. Locking ring 1506 has a plurality of solid locking ring segments 1518 retained together with connecting ring 1520 forming arcuate or “C” shaped segmented locking ring 1506. Connecting ring 1520 is comprised of a flexible material, such as spring steel, suitable for expanding and contracting locking ring 1506. Locking ring 1506 is shown in an expanded closed orientation having end faces 1534 and 1536 gap spaced. Fasteners 1521 hold connecting ring retaining links 1526 between each locking ring segment 1518 and to each end face 1534 and 1536. Retaining links 1526 have aperture 1528 a suitable to receive connecting ring 1520.

FIGS. 7A and 7B are top and side views, respectively, showing fasteners 1521 fastened to one locking ring segment 1518 in a cavity 1525 and having a head extending into a cavity 1519 in an adjacent locking ring segment 1518. Fasteners 1521 extend through apertures 1528 b, shown in FIG. 7D, fastening connecting ring retaining links 1526 between each locking ring segment 1518 and to each end face 1534 and 1536. The head of each fastener 1521, between each locking ring segment 1518, resides within a cavity 1519 within each locking ring segment 1518. Cavity 1519 has a larger diameter than the head of fastener 1521 so that when locking ring segments 1518 flex or contract in a radial direction; fasteners 1521 do not damage locking ring segments 1518.

FIG. 7C is a cross-sectional view of a solid locking ring segment 1518 and connecting ring 1520 showing the orientation therebetween. Connecting ring 1520 has a round cross-sectional configuration and is spaced from the inner circumferential surface of locking ring segment 1518 so that connecting ring 1520 does not interfere with locking ring segments 1518 when locking ring 1506 is in an expanded closing configuration. Locking ring segments 1518 have a rectangular configuration with load bearing surfaces 1522 and 1523 on axial sides thereof.

FIG. 7D shows a front view of a connecting ring retaining link 1526. Connecting ring retaining link 1526 has a rectangular lower portion for engaging ends of locking ring segments 1518 and being fastened thereto. Apertures 1528 b are suitable for extending fasteners 1521 therethrough. The top portion of connecting ring retaining link 1526 has aperture 1528 a suitable for receiving connecting ring 1520.

FIGS. 8A through 8F show alternative embodiments of sealing gaskets. Sealing gasket 1638 shown in FIG. 8A is within circumferential groove 1639 about an inner surface of door 1604 proximate an outer circumference thereof. Locking ring segment 1518 and connecting ring 1520 are shown cooperating with an outer surface of door 1604. Sealing gasket 1638 imparts a seal between the inner surface of door 1604 and a hub. In this embodiment, seal 1638 is a fluid energized seal having a smaller inner radius than groove 1639. The outer radius of seal 1638 is proximate the outer radius of groove 1639 so that seal 1638 is retained within groove 1639 when door 1604 is opened. Seal 1640, shown in FIG. 8B, has an inner and outer radius proximate the inner and outer radius of groove 1639. Both seals, 1638 and 1640, are fluid energized seals having a rectangular outer portion for seating in groove 1639 and an upper portion with a radially inward facing groove. The radially inward facing groove provides the fluid energized characteristic to the seals.

FIGS. 8C and 8D show fluid energized seals having an anti-extrusion ring. Seal 1642 has a portion for seating into a circumferential groove about an inner surface of a door. Sealing gasket 1642 imparts a seal between the inner surface of a door and a hub. In these embodiments, seals 1642 are fluid energized seals having an upper portion with radially inward facing groove 1662. Radially inward facing groove 1662 provides the fluid energized characteristic seal 1642 wherein pressure acting on groove 1662 forces seal 1642 against a door and a hub in cooperation therewith. Seal 1642 is shown having anti-extrusion ring 1650, in FIG. 8C, about an outer circumferential surface preventing seal 1642 from being extruded between the door and hub when pressure is applied at groove 1662. Anti-extrusion 1650 is a hollow ring which may be comprised of polymeric or metallic materials. For example, anti-extrusion ring 1650 may have nylon or polytetrafluoroethylene or may be comprised of a metallic spring. Seal 1642 is shown having anti-extrusion ring 1652, in FIG. 8D, about an outer circumferential surface thereof. Anti-extrusion ring 1652 has a solid ring like structure and may have a molded or extruded polymeric material or may have a metallic material. Anti-extrusion rings 1650 and 1652 may be coextruded or molded with seal 1642 or they may be structurally separate from molded or extruded seal 1642.

FIG. 8E shows fluid energized seal 1644 having anti-extrusion ring 1654. Anti-extrusion ring 1654 may be structurally separate from seal 1644 or anti-extrusion ring 1654 may coextruded or molded with seal 1644. Seal 1644 has a rectangular portion for seating into a circumferential groove about an inner surface of a door. Radially inward facing groove 1664 provides the fluid energized characteristic seal 1644 wherein pressure acting on groove 1664 forces seal 1644 against a door, a hub, and anti-extrusion ring 1654. Anti-extrusion ring 1654 has a band like configuration where a portion of anti-extrusion ring 1654 fits into the circumferential groove about the door. Anti-extrusion ring 1654 may be comprised of polymeric or metallic materials.

FIG. 8F shows spring energized seals 1646 and 1648 respectively. Spring 1656 is a cantilever spring which serves to energize seal 1646 by providing an expanding force to a portion thereof as shown. Cantilever spring 1656 may be comprised of a metallic material or polymeric material such as polytetrafluoroethylene. The spring serves to energize seal by providing an expanding force to a portion thereof as shown and may be a helical wound metallic spring or have an annular ring configuration. Advantageously, an annular ring configured spring is comprised of an elastic polymeric material. 

1. A pressure retaining closure for an opening in a pipe, vessel, or hub extending therefrom comprising: a round door having an inner and outer surface; an arcuate locking ring having a plurality of arcuate locking ring segments and at least one connecting ring movably retained therewith proximate an outer circumference of said outer surface of said door; at least one cavity having a rounded cross-section extending through the arcuate length of each of said plurality of arcuate locking ring segments; said at least one connecting ring having a round cross-section and arcuately extending through each of said cavities of said locking ring segments retaining each of said locking ring segments together forming said locking ring; said at least one cavity having a greater cross-sectional area than the cross-sectional area of said connecting ring extending therethrough; and said arcuate locking ring being suitable to expand and contract wherein an outer circumferential portion of said locking ring is suitable to engage a groove within an inner circumferential surface of said opening when said locking ring is in an expanded orientation and is suitable to contract to a circumference less than the inner circumference of said opening.
 2. The pressure retaining closure of claim 1 wherein said cross-section of said at least one connecting ring and said cross-sectional area of said at least one cavity is round.
 3. The pressure retaining closure of claim 1 wherein said cross-section of said at least one connecting ring and said cross-sectional area of said at least one cavity is oval.
 4. The pressure retaining closure of claim 1 wherein said connecting ring is solid.
 5. The pressure retaining closure of claim 1 wherein said connecting ring is hollow.
 6. The pressure retaining closure of claim 1 wherein each of said at least one cavity in each of said locking ring segments has an arcuately extending opening therein.
 7. The pressure retaining closure of claim 6 wherein each of said arcuately extending openings are in an axial surface of each of said locking ring segments.
 8. The pressure retaining closure of claim 7 wherein at least one of said arcuately extending openings is in an axially inward facing surface of each of said locking ring segments, said axially inward facing surface being proximate said outer surface of said door.
 9. The pressure retaining closure of claim 7 wherein at least one of said arcuately extending openings is in an axially outward surface of each of said locking ring segments, said axially outward surface facing away from said outer surface of said door.
 10. The pressure retaining closure of claim 1 wherein each of said at least one cavities has an arcuately extending axially outward opening with a width less than the diameter of said connecting ring therein.
 11. The pressure retaining closure of claim 1 having at least two cavities in each of said plurality of locking ring segments and at least two connecting rings.
 12. The pressure retaining closure of claim 11 wherein each of said cavities has an arcuately extending axially outward opening with a width greater than the diameter of said connecting ring therein and a connecting ring retaining link between at least two of said arcuate locking ring segments, said connecting ring retaining link having at least one aperture receiving each of said connecting rings.
 13. The pressure retaining closure of claim 1 wherein said locking ring has an inner and outer load bearing surface, said inner and said outer load bearing surfaces being substantially frustoconical.
 14. The pressure retaining closure of claim 1 wherein each of said cavities has an arcuately extending axially outward opening with a width proximate the diameter of said connecting ring therein, each of said locking ring segments having at least one adjacent circumferential end with either a protuberance or a recess suitable for receiving said protuberance, and a connecting ring retaining link with at least one aperture suitable to receive said protuberance and said connecting ring between at least two of said adjacent circumferential ends.
 15. A pressure retaining closure comprising: a round door having an inner and outer surface; an arcuate locking ring having a plurality of arcuate locking ring segments and at least one connecting ring movably retained proximate an outer circumference of said outer surface of said door; at least one cavity extending through the arcuate length of each of said plurality of arcuate locking ring segments, said at least one cavity having an arcuately extending axial opening in each of said plurality of arcuate locking ring segments; said at least one connecting ring arcuately extending through each of said cavities of said locking ring segments retaining each of said locking ring segments together forming said locking ring; said at least one cavity having a greater cross-sectional area than the cross-sectional area of said connecting ring extending therethrough; and said arcuate locking ring being suitable to expand and contract wherein an outer circumferential portion of said locking ring is suitable to engage a groove within an inner circumferential surface of an opening in a pipe, vessel, or hub extending therefrom when said locking ring is in an expanded orientation and is suitable to contract to a circumference less than the inner circumference of said opening.
 16. The pressure retaining closure of claim 15 wherein said outer cross-sectional surface of said at least one connecting ring and said cross-sectional area of said at least one cavity is rectangular.
 17. The pressure retaining closure of claim 15 wherein said outer cross-sectional surface of said at least one connecting ring and said cross-sectional area of said at least one cavity is rounded.
 18. The pressure retaining closure of claim 15 wherein said connecting ring is solid.
 19. The pressure retaining closure of claim 15 wherein said connecting ring is hollow.
 20. The pressure retaining closure of claim 15 wherein each of said arcuately extending axially openings have a width proximate the diameter of said connecting ring therein, each of said locking ring segments having at least one adjacent circumferential end with either a protuberance or a recess suitable for receiving said protuberance, and a connecting ring retaining link with at least one aperture suitable to receive said protuberance and said connecting ring between at least two of said adjacent circumferential ends.
 21. The pressure retaining closure of claim 15 having at least two cavities in each of said plurality of locking ring segments and at least two connecting rings.
 22. The pressure retaining closure of claim 21 wherein each of said cavities has an arcuately extending axially outward opening with a width greater than the diameter of said connecting ring therein and a connecting ring retaining link between at least two of said arcuate locking ring segments, said connecting ring retaining link having at least one aperture receiving each of said connecting rings.
 23. The pressure retaining closure of claim 15 wherein said locking ring has an inner and outer load bearing surface, said inner and said outer load bearing surfaces being substantially frustoconical.
 24. The pressure retaining closure of claim 15 wherein at least one of said arcuately extending openings is in an axially inward facing surface of each of said locking ring locking ring segments, said axially inward facing surface being proximate said outer surface of said door.
 25. The pressure retaining closure of claim 15 wherein at least one of said arcuately extending openings is in an axially outward surface of each of said locking ring segments, said axially outward surface facing away from said outer surface of said door.
 26. A pressure retaining closure for an opening in a pipe, vessel, or hub extending therefrom comprising: a round door having an inner and outer surface; an arcuate locking ring having a plurality of arcuate locking ring segments and at least one connecting ring movably retained proximate an outer circumference of said outer surface of said door; at least one rounded cavity extending through the arcuate length of each of said plurality of arcuate locking ring segments, said at least one cavity having an arcuately extending axial opening in each of said plurality of arcuate locking ring segments; said at least one connecting ring having a rounded outer cross-sectional surface and arcuately extending through each of said cavities of said locking ring segments retaining each of said locking ring segments together forming said locking ring; said at least one cavity having a greater cross-sectional area than the cross-sectional area of said connecting ring extending therethrough; and said arcuate locking ring being suitable to expand and contract wherein an outer circumferential portion of said locking ring is suitable to engage an inner annular groove within an inner circumferential surface of said opening when said locking ring is in an expanded orientation and is suitable to contract to a circumference less than the inner circumference of the opening.
 27. The pressure retaining closure of claim 26 wherein said locking ring has an inner load bearing surface and an outer load bearing surface, said inner load bearing surface being adapted to cooperate with an outer perimeter portion of said outer surface of said door and said outer load bearing surface being adapted to cooperate with said inner annular groove.
 28. The pressure retaining closure of claim 27 wherein said load bearing surfaces are substantially frustoconical.
 29. The pressure retaining closure of claim 27 wherein said load bearing surfaces form an angle with respect to a central axis of said locking ring of at least 30°.
 30. The pressure retaining closure of claim 29 wherein said load bearing surfaces are substantially parallel.
 31. The pressure retaining closure of claim 26 wherein said outer surface of said door has a tapered portion proximate the outer circumference thereof.
 32. A pressure retaining closure for an opening in a pipe, vessel, or hub extending therefrom comprising: a round door having an inner and outer surface; an arcuate locking ring having a plurality of arcuate locking ring segments slidingly retained proximate an outer circumference of said outer surface of said door, said arcuate locking ring having two end faces and being suitable to radially expand and contract altering a distance between said two end faces; a connecting ring retaining link fastened between each of said arcuate locking ring segments and each of said end faces of said arcuate locking ring, each of said connecting ring retaining links having a portion extending radially inward from an inner radial surface of said arcuate locking ring, said inward extending portion having an aperture therein; and a connecting ring arcuately extending through each of said apertures of said connecting ring retaining links retaining each of said locking ring segments together forming said arcuate locking ring.
 33. The pressure retaining closure of claim 32 wherein said arcuate locking ring segments are solid.
 34. The pressure retaining closure of claim 32 wherein said arcuate locking ring segments have a rectangular cross-sectional configuration.
 35. The pressure retaining closure of claim 32 wherein said connecting ring retaining links are fastened between each of said arcuate locking ring segments with at least one fastener having a head, each of said arcuate locking ring segments having said at least one fastener head extending thereto has a cavity suitable for receiving one of said at least one fastener head.
 36. The pressure retaining closure of claim 35 wherein each of said at least one cavity has a diameter greater than said fastener head being received therein by an amount sufficient to allow said locking ring segments to flex or contract in a radial direction wherein said fastener heads do not damage said locking ring segments.
 37. The pressure retaining closure of claim 36 wherein said inner surface of said door has a molded seal within a circumferential groove proximate an outer circumference thereof. 